Btu

noun

ˌbē-ˌtē-ˈyü How to pronounce Btu (audio)
: british thermal unit

Word History

First Known Use

1882, in the meaning defined above

Time Traveler
The first known use of Btu was in 1882

Browse Nearby Words

btry
Btu
BTW
See all Nearby Words

Cite this Entry

“Btu.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/Btu. Accessed 10 Sep. 2025.

Copy Citation

Share

Kids Definition

Medical Definition

Btu

abbreviation
British thermal unit
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

Using Bullet Points ( • )

Merriam-Webster’s Great Big List of Words You Love to Hate

How to Use Em Dashes (—), En Dashes (–) , and Hyphens (-)

A Guide to Using Semicolons

The Difference Between 'i.e.' and 'e.g.'
See More

Popular in Wordplay

See More

Great Big List of Beautiful and Useless Words, Vol. 3

Our Best Historical Slang Terms

Birds Say the Darndest Things

Even More Bird Names that Sound Like Insults (and Sometimes Are)

Better Ways to Say 'This Sucks'
See More

Popular

See More

Using Bullet Points ( • )

Great Big List of Beautiful and Useless Words, Vol. 3

Our Best Historical Slang Terms
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
Missing Letter A daily crossword with a twist
speech-bubble-untangle
Simplify The Convoluted Expression Quiz A quiz that’s as “uncomplicated as a round de...
See All